The DNA tumor viruses, SV40 and polyoma, are able to replicate in certain cells and to transform others. Because they contain a small amount of genetic information, they provide a useful model system for studying the infection of animal cells by viruses which leads ultimately to cell lysis, an abortive infection of transformation. The major objectives of the proposed research are to define and to characterize the gene products of Sv40 and polyoma, i.e., the messenger RNA and the proteins which are virus coded. A new technique is presented in this proposal which is to be used to determine the transcription patterns of viral messenger RNA. The virus coded proteins will be synthesized in vitro in the wheat germ cell-free system using, as messenger, virus specific RNA isolated from infected cells and RNA synthesized by the E. coli RNA polymerase with SV40 and polyoma DNA as templates. We have recently synthesized in vitro and two late proteins of polyoma (VP 1 and VP 2) and the early SV40 protein (T antigen). Eventually these studies will allow the construction of a physical map correlating viral DNA sequences with viral messenger RNA sequences and viral coded proteins. Additional studies are to be performed on the early virus coded protein, T antigen, to determine whether there are any unique characteristics which can be exploited to assay for the presence of transformation.